221866670 has 16 divisors (see below), whose sum is σ = 408648240. Its totient is φ = 86682624.

The previous prime is 221866651. The next prime is 221866679. The reversal of 221866670 is 76668122.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221866679) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 257555 + ... + 258414.

It is an arithmetic number, because the mean of its divisors is an integer number (25540515).

Almost surely, 2^221866670 is an apocalyptic number.

221866670 is a deficient number, since it is larger than the sum of its proper divisors (186781570).

221866670 is a wasteful number, since it uses less digits than its factorization.

221866670 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 516019.

The product of its (nonzero) digits is 48384, while the sum is 38.

The square root of 221866670 is about 14895.1894919132. The cubic root of 221866670 is about 605.3836512049.

The spelling of 221866670 in words is "two hundred twenty-one million, eight hundred sixty-six thousand, six hundred seventy".